This proposal seeks support for the meeting on Neuronal Circuits: from Structure to Function to be held at Cold Spring Harbor Laboratory March, 2012. The meeting will assemble leaders in the field, together with junior faculty, postdoctoral fellows and graduate students, to discuss the latest advances that analyze structure and function of nervous systems on the level of neuronal circuits in a variety of organisms and systems. Computation in neuronal circuits is perhaps the major unresolved problem in biology and provides a missing link between genes and behavior. We believe that the problem of such magnitude requires joint efforts among scientists working on different organisms and systems. Creating such synergy served as a motivation for starting this biannual meeting series. By now, this is a well-established and highly regarded in the community meeting, which has an unusual inter-species flavor and focus on circuit structure and function. By its very nature, research presented in the meeting is highly interdisciplinary as it brings together experimentalists, theorists, engineers and researchers from a range of quantitative disciplines. The meeting will include sessions on visual processing, chemosensation, locomotion, learning and memory, innate behavior and advanced techniques. Each session will be chaired by a leading scientist in the field. Oral presentations will be given be a group of distinguished invited speakers as well as selected from submitted abstracts by the meeting organizers. Selected speakers will include graduate students, postdoctoral fellows and junior faculty aiming for maximal inclusion of young investigators. Of special importance are the two poster sessions, where many participants can present their work in an atmosphere conducive to informal discussion. The meeting will be of moderate size and we expect about 250 people to attend, the vast majority of whom will be presenting a poster or talk.